Akikazu Kawase

Long-Term Outcomes of 50 Cases of Limited-Resection Trial for Pulmonary Ground-Glass Opacity Nodules

Introduction: From 1998 to 2002, we performed a trial of prospective limited resection for pulmonary ground-glass opacity lesions 2 cm or smaller. This is the second report on the long-term outcome. Methods: The enrollment criteria of the trial were as follows: pulmonary peripheral nodule less than 2 cm, diagnosis or suspected diagnosis of clinical T1N0M0 carcinoma with ground-glass opacity and lack of evident pleural indentations or vascular convergence on high-resolution computed tomography. Limited-resection (wedge or segment) specimens were intraoperatively examined by frozen section. If the nodule was confirmed as Noguchi type A or B with a resection margin of greater than 1 cm, the incision was sutured and the patient followed up. The median surveillance period was 10 years. Results: In a total of 50 enrolled participants, there were two Noguchi type A, 23 type B and 15 type C adenocarcinomas; five atypical adenomatous hyperplasias, four fibroses, and one granuloma. Although there were no patients with recurrence within the first 5 years, in four patients who underwent limited-resection pulmonary adenocarcinoma developed more than 5 years after the initial resection, of either cut-end recurrence or metachronous primary disease. Conclusions: Of 26 patients who underwent limited resection, adenocarcinoma developed in four after more than 5 years. These were possibly cut-end recurrences. We concluded that 5 years is not a sufficient period for follow-up, and that limited resection should still be done only in a trial setting, even for small ground-glass opacity lesions.

Visceral Pleural Invasion Classification in Non-Small- Cell Lung Cancer in the 7th Edition of the Tumor , Node, Metastasis Classification for Lung Cancer: Validation Analysis Based on a Large-Scale Nationwide Database

Objective: In the 7th tumor, node, metastasis (TNM) classification, visceral pleural invasion (VPI) is defined as invasion beyond the elastic layer, including invasion to the visceral pleural surface, and T1 tumors with VPI are upgraded to T2a. To validate this, we analyzed the survival of non–small-cell lung cancer patients from a nationwide database and evaluated the prognostic impact of VPI. Methods: The clinicopathological characteristics and prognosis of 4995 patients who were included in the registry study of the Japanese Joint Committee of Lung Cancer Registry were retrospectively analyzed with a special interest in the prognostic impact of VPI. These patients underwent surgery in 2004 and were pathologically staged as T1a-3N0. VPI was defined as including PL1 and PL2 according to the 7th TNM Classification, but the Japanese Joint Committee of Lung Cancer Registry did not collect data regarding staining or how extensively VPI was evaluated in each participating institution. Results: The survival differences were statistically significant between PL0 and PL1, PL1 and PL2, as well as PL2 and T3. There were no significant survival differences between T1a with VPI and T1b without VPI, or between T1a with VPI and T2a without VPI. There were no significant survival differences between T1b with VPI and T2a without VPI, or between T1b with VPI and T2b without VPI. There were no significant survival differences between T2a with VPI and T2b without VPI, or between T2b with VPI and T2b without VPI. T3 showed significantly worse prognosis than T2a with VPI and T2b with VPI. Conclusions: In addition to the current TNM classification recommendations, in which T1 tumors with VPI are upgraded to T2a, T2a tumors with VPI should be classified as T2b.

Clinical significance of PD-L1 and PD-L2 copy number gains in non-small-cell lung cancer

New reliable biomarkers are needed to predict the response to immune checkpoint inhibitors against programmed death-1 (PD-1) and its ligand (PD-L1), because PD-L1 expression on tumor cells has limited power for selecting patients who may benefit from such therapy. Here we investigated the significance of PD-L1 and PD-L2 gene copy number gains using fluorescence in situ hybridization as well as PD-L1 and PD-L2 expression in 654 patients with resected non-small-cell lung cancer. The prevalence of PD-L1 amplification and polysomy was 3.1% and 13.2%, respectively. The PD-L1 gene copy number status was in agreement with both the PD-L2 and Janus kinase 2 gene copy number statuses. PD-L1 and PD-L2 expression was observed in 30.7% and 13.1%, respectively. Both PD-L1 copy number gains and expression were associated with smoking-related tumors. Tumor cells with PD-L1 genomic gains exhibited significantly higher levels of PD-L1 expression than those without, but PD-L2 copy number gains were not related to PD-L2 augmentation. PD-L1 gene amplification and polysomy were independently associated with PD-L1 expression, with high immune infiltrates and EGFR expression in a multivariate logistic regression model. Comparative analysis between primary tumors and synchronous regional lymph node metastases revealed that the PD-L1 gene copy number alterations were highly consistent and reproducible compared with the PD-L1 expression. Both PD-L1 amplification and level of protein expression were predictors of poor survival using Cox univariate analyses. Therefore, we conclude that an increase in PD-L1 gene copy number can be a feasible alternative biomarker for predicting response to anti-PD-1/PD-L1 therapy.

Differences Between Squamous Cell Carcinoma and Adenocarcinoma of the Lung: Are Adenocarcinoma and Squamous Cell Carcinoma Prognostically Equal?

OBJECTIVE We analyzed pulmonary squamous cell carcinoma and adenocarcinoma patient survival in our single institution database, to evaluate the relationship of histologic analysis to survival and tumor aggressiveness. METHODS We reviewed 1856 consecutive patients with surgically resected pulmonary squamous cell carcinoma or adenocarcinoma regarding their clinicopathologic characteristics, overall survival and recurrence-free proportion. RESULTS In squamous cell carcinoma patients, there were more elderly male smokers and more patients with T2-4 tumors, moderately/poorly differentiated tumors, lymph node metastasis or vascular invasion than in adenocarcinoma patients. In all patients and in pN0 patients, patients with squamous cell carcinoma showed significantly poorer overall survival than those with adenocarcinoma, but there were no statistically significant differences in the recurrence-free proportion between the two histologic types. There were statistically significantly more lung cancer-specific deaths in patients with adenocarcinoma than in patients with squamous cell carcinoma (P= 0.001). CONCLUSIONS There were no differences in the development of recurrence between squamous cell carcinoma and adenocarcinoma of the lung, but considerable differences in overall survival were observed between the two histologic types. According to the stage grouping strategy of the TNM Classification for Lung and Pleural Tumours, these two histologic types need to be staged differently. This survival difference, however, may reflect the difference in patient background rather than in biologic aggressiveness between the two histologic types.

Visceral pleural invasion classification in non-small cell lung cancer

Objective: We analyzed non-small cell lung cancer patient survival in our single institution database to evaluate the effect of visceral pleural invasion (VPI) on survival and to propose a method of incorporating VPI into T-status classification in future staging systems. Methods: We reviewed 2725 consecutive surgically resected non-small cell lung cancer patients with T1a, T1b, T2a, T2b, or T3 tumors for their clinicopathologic characteristics and prognoses. Visceral pleural invasion was classified using the criteria of the 7th edition of the TNM Classification for Lung and Pleural Tumors. Results: There were no significant differences in survival between PL1 and PL2 patients. Therefore, we decided to combine the PL1 and PL2 patient groups into a single VPI+ group, and compare survival with a PL0 (VPI−) group to analyze the effect of VPI on T classification. The best survival was observed in patients with a T1a/VPI− tumor, followed by those with a T1b/VPI− tumor. In comparison, survival was similarly worse among patients with a T1a/VPI+, T1b/VPI+, T2a/VPI−, or T2b/VPI− tumor. The worst survival was observed in patients with a T2a/VPI+, T2b/VPI+ or T3 tumor. Conclusions: Otherwise T2 tumors with VPI, regardless of size, may be classified as T3 tumors in the next edition of the TNM Classification for Lung and Pleural Tumors.

Prognostic impact of CD73 and A2A adenosine receptor expression in non-small-cell lung cancer.

In immune cells, CD73 dephosphorylates and converts extracellular AMP into adenosine, which binds the A2A adenosine receptor (A2AR). Blockade of this interaction, which induces an immunosuppressed niche in the tumor microenvironment, represents a potential novel treatment strategy. The clinical significance of CD73 and A2AR expression in non-small-cell lung cancer (NSCLC), however, has yet to be thoroughly investigated. Here we evaluated CD73 and A2AR protein expression levels using immunohistochemistry in tissue microarrays containing 642 resected NSCLC specimens. Furthermore, we compared the expression profiles of 133 paired primary tumors and lymph node metastases. CD73 and A2AR expression levels were significantly higher in females than in males, in never smokers than in ever smokers, and in adenocarcinomas than in squamous cell carcinomas. Among adenocarcinomas, significantly higher CD73 and A2AR expression was observed in TTF-1-positive and mutant EGFR-positive tumors than in their counterparts. Compared with CD73, A2AR expression was more inconsistent between primary tumors and lymph node metastases. Among NSCLC patients, high CD73 expression was an independent indicator of poor prognosis in multivariate Cox regression analyses for overall survival [hazard ratio (HR), 2.18; 95% confidence interval (CI), 1.38–3.46] and recurrence-free survival (HR, 2.05; 95% CI, 1.42–2.95). In contrast, high A2AR expression was an independent predictor of favorable prognosis for overall survival (HR, 0.70; 95% CI, 0.50–0.98) and recurrence-free survival (HR, 0.74; 95% CI, 0.56–0.97). Together, these findings indicate that CD73 and A2AR have opposing prognostic effects, although cases involving CD73 or A2AR expression share some clinicopathological features.

The clinical outcome of non-small cell lung cancer patients with adjacent lobe invasion: the optimal classification according to the status of the interlobar pleura at the invasion point

OBJECTIVES The aim of this study was to analyse the survival of non-small cell lung cancer (NSCLC) patients with adjacent lobe invasion (ALI) with emphasis on the interlobar fissure status at the tumour invasion point. METHODS We retrospectively evaluated 2097 consecutive patients with surgically resected NSCLC from July 1993 through April 2006. Of these, 90 (4.3%) patients had tumours with ALI. We divided ALIs into two types by histological examination using elastic stains: direct ALI beyond the incomplete fissure (ALI-D, n = 18) and ALI across the interlobar fissure (ALI-A, n = 72), and compared the clinicopathological features and survival. RESULTS The patients with ALI demonstrated an intermediate survival between T2a and T2b tumours (5-year overall survival: T2a, 61.0%; ALI, 59.6%; T2b, 49.2%). There were distinct survival differences between the patients with ALI-A and ALI-D (5-year overall survival: ALI-D, 85.7%; ALI-A, 52.0%; P = 0.010). The survival of patients with ALI-A was not statistically different from that of patients with T2b tumours, regardless of the tumour size (P = 0.846). The survival of the patients with ALI-D did not statistically differ from those with T1a or T1b tumours (P = 0.765 and 0.418, respectively). CONCLUSIONS Our results indicate that the interlobar fissure status affects the survival of the patients with ALI. ALI should be examined by elastic stains and only ALI-A should be classified as true ALI. We propose that ALI-A tumours with a size of ≤ 5 cm should be assigned to T2b, but ALI-D tumours do not require an adjustment of the T descriptor.

Clinicopathological and Survival Analysis of Japanese Patients with Resected Non-Small-Cell Lung Cancer Harboring NKX2-1, SETDB1, MET, HER2, SOX2, FGFR1, or PIK3CA Gene Amplification

Introduction: Gene amplification is an important genetic change in cancer cells. We investigated the prevalence, clinicopathological characteristics, and prognostic value of NKX2-1 (also known as TTF-1), SETDB1, MET, HER2, SOX2, FGFR1, and PIK3CA amplification in Japanese patients with non–small-cell lung cancer (NSCLC). Methods: The copy numbers of the seven above-mentioned genes were assessed using fluorescence in situ hybridization in a tissue microarray containing 282 surgically resected NSCLC specimens (164 adenocarcinoma [AC], 99 squamous cell carcinoma [SCC], and 19 others). Clinicopathological information were obtained from the medical records. Results: NKX2-1, SETDB1, MET, HER2, SOX2, FGFR1, and PIK3CA gene amplification were observed in 30 of 277 (10.8%), 16 of 280 (5.7%), 38 of 278 (13.7%), 8 of 270 (3.0%), 34 of 278 (12.2%), 18 of 282 (6.4%), and 53 of 278 (19.1%) cases, respectively. Coamplification was detected in 16 of 156 (10.3%) AC patients and 35 of 93 (37.6%) SCC patients (p < 0.0001). NKX2-1 amplification was significantly related to an AC histology (p = 0.004), whereas SOX2, FGFR1, and PIK3CA amplifications were related to a SCC histology (p < 0.0001). Within the ACs, NKX2-1 and SETDB1 amplifications were markers of a shorter survival period. A multivariate Cox proportional hazards model revealed that NKX2-1 amplification was an independent predictor of poor survival (hazard ratio, 2.938; 95% confidence interval, 1.434–6.022; p = 0.003). Coamplification had impact on patient outcome in AC but not in entire NSCLC and SCC. Conclusions: The amplification status differed among the histological types of NSCLC. NKX2-1 amplification was an independent and the most practically important predictor of a poor prognosis among Japanese patients with AC.

Pleomorphic carcinoma of the lung expressing podoplanin and calretinin

Pleomorphic carcinoma (PC) of the lung is classified as a subtype of sarcomatoid carcinoma of the lung, and peripheral PC is sometimes difficult to differentiate from the sarcomatoid component of mesothelioma. An 80‐year‐old man was referred to National Cancer Center Hospital East because a chest X‐ray showed an abnormal shadow. CT scans of the chest indicated two solid masses located in the right lower lobe, and CT‐guided needle biopsy yielded spindle‐shaped tumor cells that were immunoreactive for both podoplanin and calretinin. Mesothelioma could not be ruled out, and the tumors were surgically resected to facilitate definitive pathological diagnosis. Both tumors were composed of undifferentiated carcinoma, bronchioloalveolar carcinoma and spindle cell carcinoma, and spindle cell component was immunoreactive for podoplanin and calretinin. Ten other tumors diagnosed as peripheral PC were also tested for podoplanin and calretinin expression. The sarcomatoid component in four of the 11 cases (36%) was immunoreactive with podoplanin, and it was calretinin positive in nine of the 11 cases (82%). When making the differential diagnosis between PC and the sarcomatoid component of mesothelioma, care is required in diagnosing biopsy specimens of peripheral lung spindle‐cell tumors that are positive for both podoplanin and calretinin.

Visualization of phosphatidylcholine (16:0/16:0) in type II alveolar epithelial cells in the human lung using imaging mass spectrometry

Imaging mass spectrometry (MS) is an emerging technique that can detect numerous biomolecular distributions in a non‐targeting manner. In the present study, we applied a mass imaging modality, mass microscopy, to human lung tissue and identified several molecules including surfactant constituents in a specific structure of the lung alveoli. Four peaks were identified using imaging MS, and the ion at m/z 772.5, in particular, was localized at some spots in the alveolar walls. Using an MS/MS analysis, the ion was identified as phosphatidylcholine (PC)(16:0/16:0), which is the main component of lung surfactant. In a larger magnification of the lung specimen, PC (16:0/16:0) was distributed in a mottled fashion in a section of the lung. Importantly, the distribution of PC (16:0/16:0) was identical to that of anti‐SLC34A2 antibody immunoreactivity, which is known to be a specific marker of type II alveolar epithelial cells, in the same section. Our experience suggests that imaging MS has excellent potential in human pathology research.